Hi,
This sounds related to another thread posted earlier: "APM transactions displayed in wrong time order".
A fix was applied here: https://github.com/elastic/kibana/issues/24072. As of this time it has not yet been released, but will be released with Kibana 7.2.
To verify that this actually solves your problem, can you please post the XHR response for the "/traces" endpoint. The url will look like:
<host>/apm/traces/88cf30e3cf1b935d976238b0d92ec81a?start=2019-04-24T11%3A01%3A31.927Z&end=2019-04-25T11%3A01%3A31.927Z